Australia centre Tim Horan (pictured) is in doubt for Saturday's World Cup semi-final against South Africa at Twickenham after being laid low by a stomach virus. The veteran was up all night vomiting and stayed at the team hotel to recuperate while the rest of the team trained on Friday morning. However team doctor John Best said he is confident Horan will be fit to play. "He's had nausea and cramping and with this there is a concern that his energy level might be low," Best said. "You don't know until you review him, but I expect he'll be fit to play. He's resting and taking medicine to make him more comfortable."